Guadua Taxonomic chacoensis Identity, (Poaceae: Morphology, Bambuseae), and its Affinities Ximena Londono Institute* Vallecaucano de Investigaciones Cientificos-INCIVA, Apartado Aereo 5660, Cali, Colombia Paul M. Peterson Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560, U.S.A. ABSTRACT.Anewcombination,Guaduachacoen¬ sis, is made. Based on morphological evidence, G. chacoensis appears closely allied to G. trinii. A detailed illustration of the species is included, and morphologicaldescriptionsandillustrationsofthe seedlingandfruitareprovided. GuaduawassegregatedfromthegenusBambusa SchreberanddescribedbyKunth(1822).Important diagnosticcharactersthatdistinguishthisgenusare triangular culm leaves in which the margins of the sheathandbladeareusuallycontiguous,adistinctive handofshortwhitehairsaboveandbelowthenodal line,synflorescenceswith2-tomany-floweredpseudospikelets,apaleaoffirmtexturewithprominent wingsemanatingfromthekeels,andthepresence of stomata and papillae on the adaxial surface of the leaf blades (Soderstrom & Ellis, 1987; Soderstrom & Londono, 1987). Other characters useful indistinguishingamongthespeciesofthegenusare theshapeofculmandfoliageleaf,thestructureand shapeofpseudospikelets,andthehabitoftheplant. GuaduaoccursthroughouttropicalAmerica,from MexicotonorthernArgentina,andcontainsperhaps 30 species. Along with Guadua, four other genera are placed in the subtribe Guaduinae: Criciuma Soderstrom & Londono and Eremocaulon Soder¬ strom & Londono from Brazil, and Olmeca Soder¬ strom and Otatea (McClure & Smith) Calderon & Soderstrom,fromMexico(Soderstrom&Ellis,1987). Guadua chacoensis occurs in northern Argen¬ tina,southeasternBolivia,andsouthernParaguay andisoneofthethreesoutheasternmostspeciesof the genus. It is frequently misidentified as G. angustifoliaKunth.Thespecieswasdescribedin1918 bytheArgentinianbotanistNicolasRojasAcostaas Bambusa chacoensis. A type specimen was not designatedbutthelocalitydata(GeneralVedia,Depto. Bermejo, Prov. del Chaco-Argentina, and He de la Colonia Aquino, Rio Paraguay) and the common name“tacuara,”distinguishitfromtwospeciesthat occur sympatrically, G. paraguayana Doell, “picanilla,” and Guadua trinii (Nees) Ruprecht, “yatevo,” “tacuaruzu,” or “tacuara brava” (Nicora & Rugolo, 1987; Young, 1985). McClure (1973), in his annotated checklist of species,includedG.chacoensisundertheheading of unresolved specific taxa. Young (1985) treated thisspeciesasoneoftwosubspeciesinthevariable Guadua angustifolia Kunth complex and indi¬ cated a neotype. However, Young (1985) pointed outthat“thetwosubspeciescanbeseparatedusing acombinationofvegetativeandreproductivechar¬ actersbutsincethemorphologicalgapseparating them is smaller than that separating most species inthesubgenus,thetaxaareconsideredheretobe onlysubspecificallydistinct.” In this study, a comparison of floral and vege¬ tative morphology among G. chacoensis, G. an¬ gustifolia,andG.triniiispresented.Basedoncom¬ pletematerialcollectedbyCamiloQuarin,abotanist from the Universidad Nacional del Nordeste, Corrientes,Argentina,adetailedillustrationofthehabit ofG.chacoensisanddescriptionsandillustrations oftheseedlingandfruitareprovided. Cuadua chacoensis (Rojas) Londono & Peterson, comb. nov. Basionym: Bambusa chacoensis Rojas, Bull. Acad. Int. Geogr. Bot. 26: 157. 1918. TYPE: Argentina. Chaco: Departamento Bermejo, General Vedia, Riberas del Rio de Oro, 23 July 1974, Quarin et al. 2384 (neo¬ type, designated here, CTES; isoneotypes, F, G not seen, MO, US). Figure 1. Woody,thornybamboo.Rhizomespachymorph. Culms 10-20 m tall, 8-15 cm diam., green, erect belowandarchingapically;internodeshollow;nodes solitary; bud solitary, covered by a prophyll, posi¬ tioned 2-4 mm above the nodal line. Culm leaves Novon 2: 41-47. 1992. 42 Novon Figure1.Guaduaehacoensis(Rojas)Londono&Peterson.—A.Floweringbranch.—B.Leafcomplement.—C. Leafligule.—D.Culmsheath.—E.Detailofculmsheathligule,adaxialview.—F.Branchcomplement.Basedon: A, Quarin et al. 2384 , B, C, Schinnini 10956; D. Tressencs & Schinnini 1310 , E, F, Schinnini et al. 6819. 43 Volume 2, Number 1 1992 Londono&Peterson Guaduachacoensis coriaceous,lightbrowntostramineous,deciduous, the blade l A- l A as large as the sheath; sheath 2050 cm long, 8 30 cm wide, abaxially strigose to glabrescent,thecoarse,rigid,brownhairsto2mm long,easilyremoved,adaxiallyglabrous,shiny,and tessellate,auriclesandfimbriaeabsent;blade4-13 cm long, 3-8 cm wide, triangular, erect, persistent, stronglymucronateattheapex,abaxiallystrigose toglabrous,adaxiallyconspicuouslynervedandpu¬ bescentbetweenthenerves,themarginsciliatewith hyaline, deciduous hairs, up to 2.5 mm long, the junction with the sheath slightly curved to ± hor¬ izontal; inner ligule 0.8-1 mm long, glabrous, stra¬ mineous, ciliolate along the margin, following the junctionbetweenthesheathandthebladeandend¬ ing at the margins; outer ligule absent. Branching intravaginal; primary branch solitary and armed, later developing 2 or 3 secondary branches from the basal proximal nodes. Foliage leaves 7 to 9 per complement;sheathglabrous,nonauriculate,ciliate on the margins; fimbriae 2-3 mm long, restricted to the sheath summit, erect basally, wavy to curly distally, 3-5 per tuft, white-ivory; blade 10-24 cm long, 0.5-2.5 cm wide, L:W ratio 11-26:1, ex¬ tremelyvariableinsize,linear,8-14-nerved,adax¬ iallyglabroustosparselyhispid,thehairs0.5-1mm long,hyalinetobrown,antrorse,3-4rowsofprick¬ le-hairsalongonemargin,abaxiallyglabrous,with sparsely coarse, rigid, hyaline hairs mainly along themidnerve,themarginsstrigose;pseudopetiole 2-3mmlong,adaxiallypilosetoglabrous,abaxially glabrous; inner ligule 0.2-0.4 mm long, minutely pubescent,ciliateonthemarginwitherect,hyaline hairs, the hairs 0.2 mm long; outer ligule 0.1 -0.2 mmlong,minutelyciliolateonthemargin.Synflo¬ rescence 30-40(-50) cm long, usually terminating leaflessbranches,consistingof6-9coflorescences with4-7multifloweredpseudospikeletspercoflo¬ rescence; rachis glabrous. Pseudospikelet 2-5( 6) cm long, 0.4-0.5(-0.6) cm wide, robust and erect, straight,corpulent,greenwhenyoung,laterbrown tostramineous,consistingofasubtendingbract,a prophyll, 1-2 glumes, 1-2 sterile lemmas, 2-4(-6) fertileflorets,inaterminalrudimentaryanthecium; rachilla5-7mmlongbetweenflorets,hispidulous; subtending bracts 8-10 mm long, 4-5 mm wide, ovate to ovate-lanceolate, abaxially glabrous to sparselypubescent,adaxiallyminutelypubescenton thedistalV3,theapexmucronate;prophyllwinged, pubescentbetweenkeelsandciliolateonthewings, occasionallygemmiferous;glumes5-8mmlong,3 mmwide,1-2,usuallygemmiferous,broadlyovate toovate-lanceolate,7-9-nerved,mucronate,posi¬ tioned close to the prophyll, abaxially shiny, with scattered minute transparent hairs on the dorsal part,adaxiallyminutelypubescent,withtransverse venationsapically,themarginssmooth;sterilelem¬ ma 10-14 mm long, 6-10 mm wide, sometimes enclosingarudimentarypalea,usuallystramineous, mucronate,abaxiallyshinyandglabrous,adaxially minutelypubescent,themarginsscarious,smooth; fertile lemma 12-16 mm long, 7-12 mm wide, ovate-lanceolate,12-17-nerved,totallyembracing thepalea,mucronate,stramineousorpurplish,abax¬ ially covered with hyaline, appressed, sometimes spreadinghairsontheproximallA,otherwisegla¬ brous and shiny, adaxially shiny, minutely pubes¬ cent, the margins scarious, shiny, bearing a tuft of hairs distally, below the mucro, the mucro 0.8-1 mm long, brown when old; palea 6-14 mm long, 2-4 mm wide, usually shorter than the lemma, stramineous, abaxially pubescent, adaxially gla¬ brous, the sulcus 2-2.5 mm wide, 3-nerved, apiculate at the apex with a tuft of hairs, the keels winged, the wings 1-1.5 mm long, 2-3-nerved, stramineous, prolonged at the apex, ciliate on the margin,abaxiallypuberulousclosetothekeels,oth¬ erwise glabrous and shiny, adaxially glabrous, the enfoldedmargins3-nerved,glabrous.Lodicules3, transparent,many-nerved,glabrous,ciliolateonthe upper part of the margin; the anterior pair 3-5 mm long, 2-3 mm wide, the posterior one 2-3 mm long, 1.5-2 mm wide. Stamens 6; anthers 5-8 mm long, 0.5-1 mm wide, sagittate at the base, apiculate at the apex of each theca, yellowish brown. Ovary 24 mm long, 1-2 mm wide, fusiform, glabrous and shiny; style 2-3 mm long, hispidulous, darker than the ovary with 3 plumose stigmas, the stigmas 3 mm long and purple when young. Fruit 9-12 mm long, 2.5-5 mm wide, an asymmetric fusiform caryopsis, brown, glabrous; embryo 2-3 mm long, 23 mm wide, basal, circular. Distribution. Known from northern Argentina, southeasternBolivia,andsouthernParaguaywhere itoccursingalleryforestsusuallyalongstreamand river edges at elevations of 75-450 m. Additionalspecimensexamined.Argentina,corRIENTES:Depto.Capital,ArroyoRiachueloyRuta12,16 Jan. 1974 (fl), Quarin et al. 1859 (US), 15 Aug. 1974 (fl),Quarin2402(MO,US);21Dec.1974(fl),Maruhak 635 (US); 27 Nov. 1975 (fl), Quarin 3125 (MO, US); PuentePesoa,ArroyoRiachuelo,3Aug.1973,Schinnini et al. 6819 (US); Depto. Concepcion, Rincon de San Pedro, 17 Dec. 1974 (fl), Burkart et al. 30687 (MO, US),Quarin2870(MO,US);Depto.Empedrado,Ruta 12 y Rio Empedrado, 24 Oct. 1975 (fl), Quarin 3210 (MO,US);Depto.Ituzaingo,IslaApipeGrande,Pto.San Antonio, 8 Dec. 1974 (fl), Krapovickas et al. 23851 (MO, US); Rincon Ombu Chico, 4 July 1974 (fl), Kra¬ povickasetal.25470(MO,US);Depto.Mercedes,75 kmNdeMercedes,LagunaTrin,17-24Oct.1975(fl), 44 Novon Quarinetal.3182(US),mlsiones:vicinityofPto.Aguirre, 100 m, 8-10 July 1914, Curran 676 (F, NY, US); Pto. Leon, 75 100 m, 21 July 1914 (fl), Curran 677 (NY, US); Iguazu, 7 Oct. 1910, Rodriguez 486 (MO, NY, US);SanIgnacio,PenonReinaVictoria,14Jan.1976 (fl),Krapovickas<S:Cristobal28759(MO,US).CHACO: Depto.Bermejo,IslaGuascara,2July1981,Tressens & Schinnini 1310 (US); Casa lata, 28 July 1944 (fl), Rojas11719(NY).TUCUMAN:Cultivado,JardinesInsti¬ tuteMiguelLillo,procedentedeMisiones,Iguazu,26 Aug. 1976 (fl), Cuezzo s.n. (US). Bolivia, santa cruz: Prov. Sara, Rio Surutu, 1 Oct. 1925 (fl), Steinbach 7233a (F, MO, US); Prov. Ichilo, 15 km SE of Buena Vista, 375 in, 28 July 1987, Nee et al. 35397 (MO, NY);ParqueNacionalArnboro,alongRioCheyo,400 m,24ago.1985(fl),Solomon14021(MO,US,);23km S of Buena Vista along Rio Chonta, 420 m, 18 Nov. 1988 (fl). Nee 36861 (NY); along Rio Saguayo, 1.5-3 kmNEofentranceintofirstAndeanfoothills,17°38'39'S, 63°43'W, 375 in, 21 Dec. 1988 (fl), Nee 37301 (MO). Paraguay, central: Ruta 2 y Arroyo Mboiy, 2 Mar.1975(fl),Schinnini10956(US).PARACUARl:sur leborddesruisseaux,Dec.1883(fl),Balansa4346(P, US),sanPEDRO:ColoniaNuevaGermania,23Oct.1916 (fl),Rojas2311(US);altoParaguay,Primavera,16June 1957,IVoolstonG-112(NY).CAAGUAZO:Orillasarroyo Tebicuary,entreCoronelOviedoyColoniaIndependencia,15Oct.1951(fl),Burkart18741(SI,US).flEEMBUcO: BarrancaselvaticadelrioTebicuary-guazu,Jan.1944 (fl),Pavetti<£■Rojas10959(UTS). floweringculmsremaingreenoryellowishandcon¬ tinue to produce new foliage leaves. According to McClure (1966), a plant of G. angustifolia from Milagro,Ecuador,establishedunderhisdirectionat Chocola, Guatemala, and Tingo Maria, Peru, had floweredannuallyduringthedryseason. Fruit. The fruits of G. chacoensis fall on the ground,germinate,andgrowbeneaththeparent plants.Phissuggeststhattherateofsurvivalofthe seedsofG.chacoensisishigherthaninotherspecies of the genus, such as G. angustifolia , where it is comparably low (estimated at less than 1%). In G. angustifolia,theyoungovaryisoftendestroyedby insects. MaturefruitsofG.chacoensisareusuallyfound mthemiddlesectionofthepseudospikeletandfall withtherachilla,lemma,andpaleaattachedtothe base.Thecaryopsisisasymmetricalandflattened on one side with a short prolongated, hirsutulous style that persists at the apex (Fig. 2S-2U). The dorsalsurfaceofthefruithasaconspicuoushilum about as long as the fruit (Fig. 2U), and the ventral surfacehasaprominentembryotegiumorcovering at the base (Fig. 2T). A cross section of the fruit of G. chacoensis reveals the presence of a pericarp, endosperm,andembryo.Thepericarpisthin,brown, andapproximately0.1mmthick,whereastheen¬ dospermisstarchy,welldeveloped,creamy-white, andoccupiesalmostthewholediameterofthefruit (Fig. 2T). The embryo is V\- X k> the length of the whole fruit, cream-yellowish, and is located at the base of the fruit in a lateral position (Fig. 21). Upon germination of the embryo, the primary shoot is first to emerge laterally just above and adjacent to the root, and there is no internode be¬ tweenthecaryopsisandthecoleoptile.Theprimary shoot is a segmented axis of clearly positive phototropismandbearsafoliarappendageateachnode. The root grows sinuously downward, 12-15 cm, bearingmanysecondaryadventitiousrootsthrough¬ out(Fig.2W). The seedling of G. chacoensis consists of, from the base upward, a coleoptile, the first basal culm leafsheathwithanelongatedinternode,thesecond basalculmleafsheathwithanotherelongatedin¬ ternode, followed by one culm leaf sheath with a broad,ovate-lanceolatebladepositionedhorizontal¬ ly, one or several blades that develop into the first seedlingleaf,andtheterminalshoot(Fig.2V).This morphologicalpatternseemstorepresentthede¬ velopmentalsequenceofatypicalbambusoidseed¬ ling(Calderon&Soderstrom,1973). Affinities.Guaduachacoensisappearstobemost closely related to G. trinii, rather than G. angus¬ tifolia. However, in all three species the general Flowering.Theincidenceoffloweringandfruit¬ inginbamboosvariesfromonespeciestoanother (McClure,1966),andaccordingtorecordsofspec¬ imens available at F, ISC, MO, NY, and US, G. chacoensis flowered in the following years: 1883, 1914, 1925, 1944, 1951, 1957, 1975-1976, 1981, and 1985-1988. We cannot establish a reg¬ ular flowering cycle for this species; however, it is evident that after a long period without flowering, G.chacoensiscanfloweruninterruptedlyforatleast 3years.ObservationsmadebyQuarinduring19741975 indicated that the flowering culms in G. cha¬ coensisareusuallyleafless,andfruitsandseedlings are produced when most of the plant is dry. The flowering cycle of G. trinii appears to be uniqueandwellknowninthegenus(McClure,1966). It was reported by Parodi (1955), who personally observedthefloweringcyclefromthesamehered¬ itary line for a period of 30 years (1923-1953). Afterfloweringandfruitinguninterruptedlyforone year, the clump died completely (i.e., truly monocarpic). The fruits then fell to the ground and ger¬ minated. The flowering cycle of G. angustifolia has not beenestablishedyet;however,observationsofthe flowering cycle of natural stands in Valle del Cauca andQuindio,Colombia,havebeenmadebytliefirst author every year from 1979 to the present. Not all the culms in a single clump flowered, and the Volume 2, Number 1 1992 Londono&Peterson Guaduachacoensis 45 Table 1. A selective form of the culm leaves, foliage leaves, and habit are similar. Guadua chacoensis and G. trinii share the fol¬ lowingcharacters:(1)amoreorlesshorizontaljunc¬ tionbetweentheculmbladeandsheath;(2)aculm leaf inner ligule ending at the margins (Fig. ID); (3) erectandrobustpseudospikelets(Figs.1A,2A);(4) prolongation of the keels-winged at the apex; and (5) a monocarpic habit, commonly with a leafless floweringbranch.Guaduachacoensisdiffersfrom G. trinii by having abaxially glabrous pseudope¬ tioles, longer (10-24 cm) leaf blades that are gen¬ erally wider (0.5-2.5 cm), and a lemma that is longerthanthepalea(Table1). GuaduachacoensiscanbedistinguishedfromG. angustifolia by having: (1) a slightly curved and continuousinnerliguleendingatthemargins;(2)a glabrous leaf sheath (Fig. 1C); (3) a conspicuously ciliate margin of the inner ligule of the foliage leaf (Fig. 1C); (4) an adaxially pilose to glabrous pseu¬ dopetiole;(5)erectandrobustpseudospikelets;(6) a scarious margined lemma, with a tuft of hairs at the apex (Fig. 21); (7) a prolongation of the keeled wings at the apex of the palea; (8) apiculate apex ofeachanthertheca(Fig.2P);(9)anasymmetrical, fusiform caryopsis (Fig. 2S); and (10) monocarpic, leaflessfloweringculms(Table1).Thegeographic distributionofG.chacoensisiscompletelyallopatric with that of G. angustifolia , which occurs in north¬ westernSouthAmericaandPanama. Acknowledgments.WearegratefultoJoseCuatrecasas. Emmet Judziewicz, Lynn Clark, and Lars PeterKvistforadviceandsupportduringthisstudy. Special thanks are given to Alice R. Tangerini for herskillfulillustrations.Supportforthefirstauthor was provided by a Smithsonian Institution ShortTermVisitorGrant. 46 Novon Figure2.Guaduachacoensis.—A.Pseudospikeletshowingprophyll,basalbracts,andflorets.—B.Rachilla segment.—C.Prophyll,dorsalview.—D.Prophyll,ventralview.—E.Basalbract,ventralview.—F.Basalbract, 47 Volume 2, Number 1 1992 Londono&Peterson Guaduachacoensis Literature Cited Parodi, L. R. 1955. La floracion de la Tacuara brava (Guaduatrinii).RevistaArgent.Agron.22:134136. Soderstrom, T. R. & R. P. Ellis. 1987. The position ofbamboogeneraandalliesinasystemofgrass classification.Pp.225-238inT.R.Soderstrom,K. W.Hilu,C.S.Campbell&M.E.Barkworth(editors), Grass Systematics and Evolution. Smithsonian Insti¬ tution Press, Washington, D.C. - & X. Londono. 1987. Two new genera of Brazilian bamboos related to Guadua (Poaceae: Bam¬ busoideae:Bambuseae).Amer.J.Bot.74:27-39. Young,S.M.1985.TheTaxonomyandNaturalHis¬ toryoftheBambusaguaduaComplex(Poaceae: Bambusoideae).M.Sc.Thesis,UniversityofFlorida, Gainesville. Calderon, C. E & T. R. Soderstrom. 1973. Morpho¬ logicalandanatomicalconsiderationsofthegrass subfamilyBambusoideaebasedonthenewgenus Maclurolyra.SmithsonianContr.Bot.11:1-55. Kunth,C.S.1822.Voyageauxregionsequinoctiales duNouveauContinent,faiten17991804,partie 6,BotaniqueSect.5.Synopsisplantarum.[Descrip¬ tionofGuaduaangustifolia,1:252-253.] McClure, F. A. 1966. The Bamboos — A Fresh Per¬ spective.HarvardUniv.Press,Cambridge. -. 1973. Genera of bamboos native to the New World (Gramineae: Bambusoideae). Smithsonian Contr.Bot.9:1-148. Nicora, E. G. & Z. E. Rugolo De Agrasar. 1987. Los generosdegramineasdeAmericaAustral.Editorial HemisferioSurS.A.,Argentina. dorsalview.—G.Lemmawitharudimentarypaleabelow,ventralview.—H.Lemma,dorsalview.—I.Apexof lemmashowingmucroandciliolatemargin.—J.Palea,ventralview.—K.Paleashowingtheciliolatewinged-keels, dorsalview.—L.Youngpaleaenclosingandroeciumandgynoecium.—M.Youngandroeciumandgynoecium protectedbylodicules.—N.Lodiculecomplement.—O.Androeciumwith6stamens.—P.Antherapex.—Q. Gynoeciumwith3plumosestigmas.—R.Maturefloretenclosingfruitwithrachillaattachedtothebasalpoint. S.Fruitwithashortstylarcolumn,lateralview.—T.Fruitshowingtheprominentembryotegium,ventralview.— U.Fruitshowingthehilum,dorsalview.—V.Seedlingshowingthegerminatedcaryopsis.—W.Detailofthebasal portionofseedlingshowingthelemmaattachedtothefruit(1),thecoleoptile(cp),thefirstbasalculm-leafsheathof the primary shoot (s) and the root (r). Based on: A-Q, Quarin 3210; R-U, Quarin et al. 1859; V, W, Krapovicas etal.23851. Londoño, X and Peterson, P M. 1992. "Guadua chacoensis (Poaceae: Bambuseae), its taxonomic identity, morphology, and affinities." Novon a journal of botanical nomenclature from the Missouri Botanical Garden 2, 41–47. https://doi.org/10.2307/3391607. View This Item Online: https://www.biodiversitylibrary.org/item/14662 DOI: https://doi.org/10.2307/3391607 Permalink: https://www.biodiversitylibrary.org/partpdf/2486 Holding Institution Missouri Botanical Garden, Peter H. Raven Library Sponsored by Missouri Botanical Garden Copyright & Reuse Copyright Status: In copyright. Digitized with the permission of the rights holder. License: http://creativecommons.org/licenses/by-nc-sa/3.0/ Rights: https://biodiversitylibrary.org/permissions This document was created from content at the Biodiversity Heritage Library, the world's largest open access digital library for biodiversity literature and archives. Visit BHL at https://www.biodiversitylibrary.org. This file was generated 16 April 2022 at 20:08 UTC